They will also be able to seize any cash in the possession of illicit employees or found at their workplace.

The new legal armoury which will also include extra powers for tackling people-smugglers and sex traffickers, is intended by ministers to bolster the country's border defences and address public concerns over illegal immigration.

As a sign of their enhanced powers, immigration staff will be put in uniform for the first time.

The outfits, which feature navy-blue epaulettes, will be initially piloted at Heathrow, Gatwick and Stansted airports and Poole port.